The present invention relates generally to textile open-end yarn spinning operations and, more particularly, to a device for opening sliver into individual fibers and feeding the fibers to an open-end spinning device.
In open-end spinning operations, a textile sliver consisting of individual fibers, which through previous processing have been substantially parallelized with respect to one another, are opened, i.e. separated into essentially individual fibers, and fed to the spinning chamber of an open-end spinning device. Various devices exist for performing this sliver opening and feeding operation. One basic type of feeding and opening device essentially includes a housing in which a sliver opening roller is rotatably mounted, in combination with a sliver delivery member, a feed roller and some form of spring-biased pivotable or otherwise movable guide member or plate associated with the feed roller for cooperatively directing incoming sliver to the opening roller through a suitable sliver intake opening in the housing. The housing and the opening roller are cooperatively arranged to define a fiber guide pathway through the opening device through which the associated open-end spinning device applies a vacuum, for directing the individualized fibers into the spinning chamber of the open-end spinning device. In sliver feeding and opening devices of this type, an opening may be provided in the housing through which dirt and debris in the sliver may be separated from the individual fibers during the opening operation.
As will be understood, the individual fibers are relatively fine with a rather small diameter so that the fibers may tend to settle and become lodged at various locations within the housing, even at very small or fine joints or areas of unevenness at the junctures between adjacent components of the housing as well as at housing edges and corners. Fibers so caught then may pose an impediment to the normal movement of other fibers which may catch on the previously-caught fibers. In time, a flock or tuft of fibers may accumulate and significantly disturb the normal fiber flow through the housing. Further, errors or even a breakage of the yarn produced by the spinning device may occur if such a flock ultimately dislodges and passes into the spinning chamber of the open-end spinning device.
As aforementioned, sliver feeding and opening devices for open-end spinning operations are known wherein a separating opening is provided in the housing through which debris in the sliver, e.g. husk remnants, sand, dirt, finish, etc., may be expelled. One example of this type of opening and feeding device is disclosed in West German Patentschrift 19 14 115, wherein the wall surface of the housing which surrounds the opening roller to define the fiber flow pathway is provided with a separating edge which defines a separating opening at a downstream spacing from the sliver intake location to allow debris to be separated from the fibers of the sliver during the opening process under the effects of centrifugal force created.
Such a separating opening also makes possible the separation and discharge of a dislodged flock of accumulated fibers, but the separating opening cannot serve to prevent the accumulation of fibers and fiber tufts within the housing. In the known sliver feeding and opening devices, fibers typically tend to settle in joints or corners at several locations within the housing of the opening roller, e.g. between the guide plate and the housing as well as at corners formed between housing walls at the lateral sides and about the circumference of the opening roller.
U.S. Pat. No. 3,828,539 (and its counterpart West German Offenlegungsschrift 23 12 169) discloses a sliver feeding and opening device for open-end spinning applications wherein a movable sliver guide member is biased with pressure against the sliver feed roller and further includes an arcuate continuation segment which surrounds a portion of the opening roller. However, the pressure feed member is not pivotably mounted but instead is movably arranged so that the arcuate portion of the pressure feed member is movable only in a generally circular path about the opening roller and, further, the spacing of the feed member from the side walls of the housing is very small so as to form a narrow slot in which fibers may tend to settle and accumulate. If a relatively thick area of the sliver is drawn into the opening device, a danger exists that the device will become overfilled and the opening roller will catch since the arcuate portion of the feed member cannot move away from the opening roller if excess fiber is drawn in by the opening roller.